A review of the prior art of infra-red heaters will disclose that there are few heater assemblies which are satisfactory in respect to lightweight simplified construction required for use in portable or mobile heaters. It is desirable in such heaters that the heat-radiating unit may be oriented to positions of any angle including inverted positions such as obtainable by the dolly-type heater disclosed in Patent Application Ser. No. 920,488 filed June 29, 1978. The most heat-sensitive component of such heaters is the interior reflector, especially, if it comprises a light gage material such as thin polished aluminum sheet. A relatively inexpensive relfector may be used if it is adequately ventilated. However, when adequate ventilation is provided, protection is required under many uses through shielding of the reflector components from snow, rain, bird and insect debris such as, nesting materials, etc. Another heat-sensitive portion of an infra-red heater is the terminal box. Connection of the heat element with power sources is required in a manner avoiding overheating of power supply wires adjacent to the point of connection.
The uses to which an infra-red ray heater is to be subjected as contemplated herein include a great variety of stationary and mobile applications under any weather condition. The need for a durable lightweight infra-red ray heater is especially desired for mounting in a portable unit.
Hence, objects of the invention are to provide a basic unit in the form of an infra-red ray heater which is self-ventilating; constructed primarily of sheet materials to attain lightweight, weatherproof, and conveniently attachable as a unit to portable or fixed mounting apparatus. A further object is to provide a specific combination of components arranged in a unique design to achieve the aforenamed objects.